Packing for sealing high pressure fluids



Jan. 26, 1937. T K V ENT 2,068,720

PACKING FOR SEALING HIGH PRESSURE FLUIDS Filed Jan. 11, 1935 2 Sheets-Sheet 1 Inventor Thomas K-Vincent W74 WWWZ Attmr'nav T. K. VINCENT PACKING FOR SEALING HIGH PRESSURE FLUIDS 2 Sheets-Sheet 2 Jan. 26, 1937.

Filed Jan. 11, 1935 Eggs,

Inventmr Thmmas KNincent WKQQWZ Attorney Patented Jan. 26, 1937 PACG FOR SEALING MGR PRESSURE mums Thomas K. Vincent, U. S. Army, Kans.

: I. "I rttan,

Application January 11, 1935, Serial No. 1,321

7 7 Claims.

(Granted under the ac t of March 3, 1883,-as

amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon. 1

This invention relates to packing for sealing A high pressure fluids and is an improvement on the packing shown in Patent No. 1,725,836 of August In the patent the unsupported portion of the pressure transmitting side of a diflerential packing ring has an annular tongue which is disposed between inner and outer packing rings. This construction is expensive and the arrangement has failed to function-in a satisfactory manner. When the packing is subjected to high pressures,

- the cylinder is dilated by the pressure medium while the mandrel or spool retains its original diameter. The inner and outer packing rings are being compressed and naturally tend to expand radially but this is prevented in the case of the inner ring by the tongue and also by the spool.

The purpose of this invention is to provide an inexpensive packing wherein the unsupported portion of the difierential packing ring does not prevent radial expansion of the inner and outer packing rings but is arranged to utilize the expansion of the rings to efiect a seal.

- ing constructed and'arranged in accordance with packing prior to being deformed.

the invention.

Fig. 2 is a similar view showing another form of the invention.

Fig. 3 is a sectional view of a modified form of Fig. 4 is a similar view of the packing of Fig. 3 after being deformed.

Figs. 5 and 6 are sectional views showing variations of the pacln'ng of Fig. 3.

Referring to Fig. 1,'the improved packing is used, for example, in cold working apparatus wherein a cylindrical object 5, such as a gun tube, is to be subjected to a high pressure fluid with a view to permanently enlarging its bore and increasing its elastic limit. .In order to confine the fluid in the chamber 6 of the tube, the open ends of the chamber must be plugged and properly packed. A convenient method of plugging the 5 ends and at the same time reducing the area of the chamber and the amount of fluid required is to insert in the tube a mandrel or spool I of. a, suflicient length to enable the packing carried thereby to be positioned in the ends of the tube. 10

The spool has a reduced portion 8 serving to hold and guide the component parts of a packing unit and a threaded outer portion 9 for receiving a nut ill which holds the packing unit in place against the shoulder l I of the spool. 15

The packing unit consists, in the order named, of a supporting ring l2 of steel or hard metal seated on the nut Ill, radially spaced rings comprising an inner ring l3 and an outer ring M of steel, a ring 15 of brass or harder metal, a ring 20 is of a softer metal such as copper. non-metallic rings I! of leather orrubber and a steel ring [8 seated against the shoulder I I.

On admission of a high pressure medium to the chamber thepacking rings are forced outwardly towards the fixed nut ill and are accordingly compressed and moved into close contact with the spool and the cylinder. Since the efiective area of the inner ring I3 and outer ring I4 is less than the area of the ring I5 the pressure per unit of area on the inner and outer rings is greater than the pressure per unit of area on the pressure side of the ring l5 and also greater than the unit pressure exerted by the fluid. The rings 1 l3, l4 and I5 are substantially plastic when subjected to high pressure and as a result they will be compressed and will expand radially, maintaining contact with the spool and the cylinder. The pressures are so great that the rings are permanently deformed, the central portion of the brass ring l5 bulging into the space between the steel rings 13 and It. The edges of the steel rings cut into the brass ring at the bulge and establish an effective seal which prevents passage of the pressure medium.

The purpose of arranging the rings l2 to I1 in the order of their ductility is to bring them successively into play as the pressure is increased. For example the rubber and leather packing serves to prevent leakage at the start of the operation, after which the metal rings are relied on to maintain the seal as the pressure is increased. It is absolutely essential that leakage be prevented from the very start of the operation. If the pressure medium should leak past the first rings and enter the space between the inner and outer rings l3 and M the subsequenthigh pressure will cause a rupture of the end of the spool. 7,

Another form of the packing is shown in Fig. 2 and comprises a steel supporting ring IS, a pair of radially spaced brass rings 20--2l, a pair of radially spaced copper rings 22-23, non-metallic rings 24 and a steel ring 25. In this arrangement the rubber bulges into the space between the rings 22-43.

In Fig. 3 the pressure transmitting ring 26 is of steel and is formed with a short annular rib 21 which projects a short distance into the space between the inner ring 28 and the outer ring 29 which are of softer metal. When the rings are deformed on application of the pressure medium they will fold over the edge of the'rib 21 as indicated in Fig. 4. The metal of the rings and of the rib is practically fused and positively prevents passage of the fluid medium.

' An alternate arrangement is shown in Fig. 5 in which the. pressure transmitting ring 30 of steel has a rib 3| which extends through nonmetallic rings 32-33 and projects into the space between an inner copper ring34 and an outer copper ring 35. When an additional mass of metal is required a pair of brass rings 36 and 31 are placed next to the copper rings.

In Fig. 6 a simple packing comprises steel end rings 38 and 39, the ring 38 having a rib M extending through non-metallicarings ll-42 and partially between soft metal rings 43-44.

I claim: I I

1. In high pressure apparatus including concentric cylindrical members having spaced seating surfaces, a packing of adjoining rings between said members and said seating surfaces, said packing including in the order of arrangement towards the pressure side of the assembly a supporting ring, a pair of radially spaced metallic rings having unsupported adjacent faces,

a pressure-transmitting ring of softer material and greater area than the radially spaced rings, rings of different materials and having ductility decreasing towards the pressure side of the assembly, and a pressure-receiving end ring of relatively hard metal.

2. In high pressure apparatus including concentric cylindrical members having spaced seating surfaces, a packing,of adjoining rings between said members and said seating'surfaces, said packing including in the order of arrangement towards the pressure side of the assembly a supporting ring, a pair of radially spaced rings of hard metal having unsupported adjacent.

faces, and a pressure-transmitting ring of softer material and greater area than the radially spaced rings and extending across said rings.

3. In high pressure apparatus including concentric cylindrical members having spaced sea. ing surfaces, a packing of adjoining rings between said members and said seating surfaces, said packing including in the order of arrangement towards the pressure side of the assembly a supporting ring,'a pair of radially spaced rings of soft metal having unsupported adjacent faces, and a pressure-transmitting ring of harder material and greater area than the radially spaced rings and extending across-said rings.

4. In'high pressure apparatus including concentric cylindrical members having spaced seating surfacesja packing of adjoining rings between said members and said seating surfaces, said packing including in the order of arrangement towards the pressure side of the assembly a supporting ring, a pair of radially spaced metallic rings having unsupported adjacent faces, a non=metallic ring of greater area than the radially spaced rings and extending across said rings, and a metallic pressure-transmitting ring.

5. In high pressure apparatus including concentric cylindrical members having spaced seating surfaces, a packing of adjoining rings between said members and said seating surfaces,

said packing including in the order of arrangement towards the pressure side of the assembly a supporting ring, a pair of radially spaced metallic ringshaving unsupported adjacent faces,

a pressure-transmitting ring of different ductility and'greaterarea than the radially spaced rings and extending across said rings.

6. In high pressure apparatus including concentric cylindrical members having spaced seating surfaces, a packing of adjoining rings between said members and said seating surfaces, said packing including in the order of arrangement towards the pressure side of the assembly a supporting ring, a pair of radially spaced rings of soft metal, a non-metallic, ring against each one of the radially spaced rings, and a pressuretransmitting ring of hard metal having an annular rib extending between the non-metallic rings and partially into the space between the radially spaced rings of soft metal.

'7. In high pressure apparatus including concentric cylindrical membershaving spaced seating surfaces, a packing of adjoining rings be- ,tWBEH said members and said seating surfaces said packing including in the order of arrangement towards the pressure side of the assembly a supporting ring, a pair of radially'spaced rings of soft metal, and a pressure-transmitting ring of hard metal having an annular rib extending partially into the space between the soft metal rings whereby on compression of the assembly the rib will cut into the soft rings to establish a seal. 1 l

THOMAS K. VINCENT. 

